Apparatus for grinding and/or polishing glass



April 15, 1930. l v F. B. WALDRON 1,755,140

APPARATUS FOR GRINDING AND/OR POLISBING GLASS Filed July 16; 1929 Patented Apr. 15, 15930 UNITED s'ra'ras PATENT orrlca FREDERIG BARNES WALDRON, OF PRESCOT, ENGLAND, ASSIGNOR TO: PILKINGTON BROTHERS LIMITED, OF LIVERPOOL, ENGLAND, A. COMPANY REGISTERED UNDER THE LIMITED-LIABILITY COMPANIES ACTS OF GREAT BRITAIN APPARATUS FOR- GRINDING AND/OB POLISHING GLASS Application filed July 16, 1929, Serial No. 378,807, and in Great Britain September 14,1828.

This invention relates to apparatus for the rinding and polishing of plates or sheets of g ass, and particularly to t at type of apparatusin which a series of tables, on which the glass is laid, move continuously under the grinding and polishing discs.

Inthe operation of such apparatus it. is customary to interpose between the glass and the table on which it is laid, a sheet of v o cloth, rubber,-paper or other protective material (hereinafter referred to .as cloth) to a ensure thatthe glass does not come into direct contact with the table, and the object of the present invention is to facilitatethe manipulation of the said material and render its application to, and removal from, the

tables, automatic from start to finish of their operative course. To this end the invention comprises means whereby the material may be continuously applied to and removed from the tables during the continuous process.

' The material may be provided in the form of a roll supported near the starting end of the apparatus in such a position that the free end of the material may be laid upon a table commencing its operative course and be unwound from the roll by the travel of the table after the glass has been laidthereon. The

succeeding tables arriving at the start of the operative course are thus automatically supplied with the material ready for the reception of the glass, andthe laying-on is enabled to roceed uninterruptedly.

t the finishing end of the apparatus, the

35. material is connected to a mandrel or stock upon which it is wound as the glass'is removed ;from a table reaching the end of its operative course. Means may be provided for driving the last-mentioned mandrel or do stock at asuitable speed, or, referably,it'may be arran ed to be turned y the movement of the ta les. For this purpose the mandrel or, stock mtg be arranged to bear u on the tables and xed vertical guides may e providedto restrain it from moving along with p the tables.

The invention will now be described by reference .to the accompanying drawing which represents'in side elevation partly 80 broken away and more or less in diagram,

one constructional form of the improved apparatus.

For convenience of description the mandrels or stocks are hereinafter referred to only as mandrels. I

The apparatus as here illustrated, comprises two pairs of stationary brackets 1, 2, of which only one bracket of each pair is represented. On the brackets 1,, bearings 3 are fixed for supporting, with a capacity for rotation, a mandrel 4 on which is wound the supply roll 5 of the cloth 5, which lastnamed is represented in dot-and-dash lines. The brackets 2 are provided with, or constitute, .fixed vertical guides in which the mandrel 6 which receives the cloth after it has fulfilled its function, is free to rotate and also to move vertically as is necessitated by the gradual accumulation of the cloth on said mandrel, and the call for subsequent removal of the full receiving roll 5' to make way for the substitution therefor of an empty mandrel 6.

' 7 represents the tables, 8 the plates or sheets of glass which are to be supported thereon with the cloth 5 intervening between said glass and cloth, 9 the bed or base along which the series of tables 7 is propelled, and 10, 11 two of the series of grinding or polishing discs beneath which the glass is successively conveyed by the travelling tables. a

The tables 7 travel in the direction indicated by the arrow and at the commencement of operations a short length of the cloth is unwound from the supply roll 5, and on this is laid the first of the glass plates or sheets 8 so that owing to the weight of said plate, the cloth 5 is carried along with the latter and thereby automatically unwound from the sup ly roll. As the successive tables arrive beneath the cloth so are the successive plates laid onthe latter, and when the first of the plates approaches the mandrel 6 (by which time the grinding or olishing of this late will have been comp eted) this said late is lifted from the cloth 5 and the lead mg end of the cloth is made fast to the said mandrel 6. Owing then, to the weight of i the mandrel 6, and the continued travel of the tables, this mandrel will be automatically rotated and cause the soiled cloth to be wound upon it, the said mandrel gradually rising as the cloth accumulates thereon and the diameter of the receiving roll 5 thereby correspondingly increases.

Instead of the mandrel 6 and receiving roll 5 being rotated by friction derived from contact with the travelling tables (which is a desirable arrangement owing to their speed of rotation being automatically varied with the increase of diameter-of said roll) other means may be provided for rotating the mandrel 6 at the desired varying speeds.

- Having described my. invention, I declare that what I claim and desire to secure by Letters Patent is 1. In apparatus for grinding or polishing plates or sheets of glass, the combination with a series of travelling tables on which the lass is laid and a series of grinding or polis ing discs beneath which the tables are adapted to move continuously, of a roll of clean cloth located at the commencing end of the operative course of the tables, a retatable mandrel within the roll, and means adapted to unwind the cloth from the roll at the speed of travel of the tables.

2. In apparatus for grinding or polishing plates or sheets of glass, the combination with a series of travelling tables on which the glass is laid and a series of'grinding or olishing discs beneath which the tables are ac apted to move continuously, means adapted to continuously feed clean cloth on to the travelling tables at the commencement of their operative course at the speed of travel of said tables, a rotatable mandrel located at the finishing end of said operative course and means adapted to wind the cloth on to said mandrel at the speed of travel of the tables. 3. In apparatus for grinding or polishin plates or sheets of glass, the combination wit tive course of the tables, a rotatable mandrel within the roll, means adapted to unwind the cloth from the roll at the speed of travel of the tables, a rotatable mandrel locatedat' the finishing end of said 0 erative course, and means adapted to wind t e cloth on to said mandrel at the speed of travel of the tables.

4. In apparatus for grinding or polishin plates or sheets of glass, the combination wit a series of travelling tables on which the lass is laid and a series of grinding or polis 'n discs beneath which the tables are ada ted to move continuously, of a roll of clean 0 oth located at the commencing end of the operative course of the tables, a mandrel within the roll, bearings within which the mandrel turns abouta fixed axis, the cloth .being antomatically unwound from the roll through the weight of the glass laid thereon holding it in frictional contact with the travelling tablesQ J 5. In a paratus for grinding or polishing plates or s eets of glass, the combination with a series of travelling tables on which the glass is laid and a series of grinding or polishing discs beneath which the tables are adapted to move continuously, of a roll of clean cloth located at the commencing end of the operative course of the tables, a mandrel within the roll, hearings in which the mandrel turns about a fixed axis,.a mandrel for receiving the cloth at the finishing end of said operative course, and guides within which the lastnamed mandrel can ascend automatically in response to the accumulation of cloth thereon, these guides permitting the said mandrel to be rotated through the soiled cloth accumulating thereon, being in frictional engagement with the travelling tables.

6. In apparatus for grinding or polishing plates or sheets of glass, the combination with a series of travelling tables on which the glass is laid and a series of grinding or polishing discs beneath which the tables are adapted to move continuously, of a roll of clean cloth located at the commencing end of the operative course of the tables, a mandrel within the roll, hearing within which the mandrel turns about a fixed axis, a mandrel adapted to bear on the tables for receiving'the soiled cloth at the finishing end of the series of discs, and guides within which the last named mandrel can ascend automatically in response to the accumulation of cloth thereon.

In witness whereof I have aflixed my signature hereto.

FEEDER-IO BARNES WALDRON. 

